Apparatus and method for identifying a hook effect and expanding the dynamic range in point of care immunoassays

Abstract

The present invention relates to systems and methods for the rapid in situ determination of the existence of a hook effect and expansion of the dynamic range of a point of care immunoassay. For example, a system for identifying a hook effect and expanding the dynamic range of an immunoassay is provided that may include a primary sensor having first immobilized antibodies that may be configured to generate a first signal based on a presence or absence of a target analyte in a sample. The system may further include an attenuated sensor having second immobilized antibodies at a reduced concentration relative to a concentration of the first immobilized antibodies on the primary sensor and that may be configured to generate a second signal based on the presence or absence of the target analyte in the sample. The system may further include a processor configured to determine a presence of a hook effect in the immunoassay based on relative values of the first and second signals and optionally determine the target analyte concentration of the sample.

Description

CROSS-REFERENCE TO RELATED APPLICATIONS[0001]This is a non-provisional of Provisional Appl. 61 / 746,705, filed Dec. 28, 2012, the entirety of which is incorporated herein by reference.FIELD OF THE INVENTION[0002]The invention relates to analytical testing devices and methods of using same. Specifically, the invention relates to systems and methods for the rapid in situ determination of the existence of a hook effect and expanding the dynamic range in immunoassays, and in particular in point of care immunoassays.BACKGROUND OF THE INVENTION[0003]A multitude of laboratory tests for analytes of interest are performed on biological samples for diagnosis, screening, disease staging, forensic analysis, pregnancy testing, drug testing, and other reasons. While a few qualitative tests, such as pregnancy tests, have been reduced to simple kits for the patient's home use, the majority of quantitative tests still require the expertise of trained technicians in a laboratory setting using sophisti...

AI Technical Summary

Benefits of technology

[0040]In operation, therefore, one goal of the present invention is to provide a dual immunosensor cartridge that is preferably operated as follows. An unmetered amount of a preferably biological sample is placed into the sample chamber of the cartridge, and the cartridge is placed into a reading apparatus. A metered portion of the sample is amended with at least one antibody-enzyme conjugate, and is then contacted with the two immunosensors. A second fluid, which contains an electro-inactive substrate for the enzyme, is used to rinse the immunosensors substantially free of unbound antibody-enzyme conjugate, and the electrical response of the two immunosensors is recorded and analyzed for the presence, or amount of, the analyte of interest and / or the presence of a hook effect.

Problems solved by technology

Laboratory testing increases the cost of analysis and delays the results.

In many circumstances, delay can be detrimental to a patient's condition or prognosis, such as for example the analysis of markers indicating myocardial infarction.

In particular, the high concentration of target analyte may result in substantially all of the signal antibody within the immunoassay binding to free analyte in the sample, and thus an insufficient amount of signal antibody remains to bind to analyte that is bound to the capture antibodies of the immunoassay.

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